How to Witness to Roman Catholics
Many Catholics do not know what they are supposed to believe. I always start with the good person test. When you explain the gospel to them they might not realize that what you are telling them is not what they are supposed to believe. After I explain that Jesus died on the cross to pay their fine, I show them that if the fine is paid in full why would there be a place in the middle like purgatory. I take people to Luke 17 and show that Jesus only talks about heaven and hell and no other place.
The biggest difference between Christian and Catholics is the difference between infused and imputed righteousness. Christians believe in imputed righteousness. Imputed righteousness is the fact that the perfect life that Jesus lived is credited to us when we repent and trust Jesus. It is not just the fact that Jesus paid the fine, we are also credited with the perfect life that Jesus lived.
I often explain imputed righteousness like this. Imagine you are guilty before the judge. You tell the judge you are sorry and will never do it again. He says you should be sorry and you should not do it again. The judge tells you that there is a fine to be paid. You tell the judge about all the good deeds you have done. The judge says I am glad you have done all of those good deeds but they cannot pay your fine. Someone offers to pay your fine. In fact it is the judge who pays your fine and he takes your wrap sheet and applies it to himself and he gives you his perfect wrap sheet with 0 infractions on it. His wrap sheet is laminated so nothing can ever be written on it. That is what Jesus did. Jesus is the judge. Jesus came to live that perfect life that you can I could not. Jesus died on the cross to pay our fine for our sins. Jesus credits us with His righteousness. We need to repent and trust Jesus.
Infused righteousness occurs as a person goes through different religious acts. If a Catholic dies without going through all the rites then they will go to purgatory. A Catholic must also do good deeds to earn heaven.
Purgatory is where people burn off sins so they can go to heaven. The issue is that we owe an eternity in hell for each and every sin. If you even have 1 sin that you still need forgiveness for when you die how long will you be in purgatory burning? Eternity is how long you would burn in Purgatory. What is a better name for Purgatory? Hell!
The following are videos that show what they are supposed to believe. However, you need to remember when you are witnessing to non-Christians you do not want to convince them of what they are supposed to believe to get them to the truth of the gospel.